Integral to the RARAF program is the goal of making the mature TR&Ds that we have developed accessible to service users, so that they can expand their research objectives beyond their currently funded goals. In particular our aim is to provide approved users who have funded research projects access to the world's broadest range of microbeam irradiation modalities for biological experiments, including a sub-micron charged particle beam, a proton microbeam, an x-ray microbeam, a UV-microspot, and the world's only neutron microbeam. In addition, we provide broad-beam exposure facilities, including x rays, ? particles, protons and neutrons. Features of the SP-based program are: ? Making available to investigators the unique mature microbeam irradiation facilities at RARAF that will allow them to perform experiments not otherwise possible. 1. Providing support for the development of microbeam-based experiments based on existing equipment and irradiation protocols. 2. Providing a biology-friendly environment that includes support for sub-cellular, cellular, and small animal irradiations, post-exposure incubations, imaging, and sample processing. 3. Providing associated services, including physics and dosimetry support. ? Service projects are structured in a variety of experimenter specific ways. For most SPs, the investigators are present and actively involved during the microbeam irradiations. In others, the microbeam irradiations are performed on targets shipped by the PI to RARAF, after which the samples are shipped back to the PI for analysis. ? For service-based irradiations, there is a charge of $400/hour for accelerator time (includes start-up), charged in four-hour increments. These funds are used to support routine maintenance and supplies, in the year it was received. In terms of cost sharing, the LEC will consider requests for the fee to be reduced or waived, in exceptional circumstances. Sixteen service-based projects are proposed here, leveraging off our existing TR&D technology. The SP PIs include investigators with a wide range of biomedical research interests, from institutions with broad geographic coverage. All the SPs provide expansions to the SP users' currently funded peer-reviewed research, which otherwise could not be accomplished.